(一)用2％的福尔马林,加滴少许甘油,浸制黑鱼,一年来色泽保持很好,没有退色。用5％的福尔马林同时浸制的,背部颜色已经变白。 (二)以3％的福尔马林、10％的酒精和5％的甘油混合液浸制番茄,二年来仍保持原色。 (三)进行茎的运输作用的课堂观察时,让同学把青菜的带叶花茎一段插入红或蓝墨水中,只 (A) with 2% formalin, add a little glycerin, blackfish soaked, a year to maintain good color, no fading. With 5% formalin at the same time, the back color has become white. (B) Tomato soaked in 3% formalin, 10% alcohol and 5% glycerol mixture, the color remained for two years. (C) the role of the stem of the classroom observation, let students classify the vegetable with a leaf stalk inserted into the red or blue ink, only